I've ground 2nd once in this car and it's been fine since. I did it quite a few times in my 350Z with no apparent ill effects. It's not good but you don't need a new trans. Shift a little slower. That extra 0.1 second isn't worth it.
2008 IB E92 M3| BBS | KW | Arkym | Platte Forme A.G. | Active Autowerke | K&N | Fabspeed | Dinan | Evolve-R